1. Field of the Invention
This invention relates to radar processor systems and more particularly an improved mean level detection system that is substantially insensitive to the type of clutter that is encountered.
2. Description of the Prior Art
Conventional radar systems utilize adaptive thresholding devices such as mean level detectors which use a fixed sample size in range to provide an estimate of the clutter amplitude for determining the mean level detection threshold. Because clutter varies considerably in the length of its range extent, a system utilizing a fixed sample size will result in a sample that in most cases will either be too small and produce a poor estimate of the means and will be in error and provide a high threshold level or will be too large and will be in error because the sample contains clutter and noise which reduces the threshold level below the mean value of the clutter amplitude. If the threshold level is too high, a number of valid signals may not be detected and if the threshold level is too low the system has an undesirably high false alarm rate. Thus, in some types of radar systems a detection system would be desirable that does not have the mean detection level determined by a fixed sample size of the clutter in range.